Journal
CHEMISTRY-AN ASIAN JOURNAL
Volume 5, Issue 3, Pages 530-537Publisher
WILEY-V C H VERLAG GMBH
DOI: 10.1002/asia.200900510
Keywords
host-guest systems; macrocycles; NMR spectroscopy; ionic liquids; supramolecular chemistry
Categories
Funding
- Raymond and Helen Kwok Research Scholarship
- German Academic Exchange Service (DAAD)
- EPSRC [EP/F035535/1] Funding Source: UKRI
- Engineering and Physical Sciences Research Council [EP/F035535/1] Funding Source: researchfish
Ask authors/readers for more resources
The host-guest chemistry between a series of 1-alkyl-3-methyl-imidazolium bromide ([C(n)Mim]Br) guests and the macrocyclic host molecule cucurbit[6]uril (CB[6]) in an aqueous system is systematically studied in neutral aqueous media. Both 1D and 2D NMR experiments in conjunction with isothermal titration calorimetry (ITC) unveil the binding characteristics of the host-guest interaction. Solution binding constants (K-a) up to 10(5)m(-1) are measured directly. Additionally, this [C(n)mim]Br-CB[6] interaction was found to significantly increase the solubility of CB[6] in neutral water, in some cases by at least four orders of magnitude. From these studies, a detailed host-guest binding model has been constructed and is fully discussed. In this model, the delocalized positive charge on the imidazolium ring becomes partially localized on either one of the nitrogen atoms upon complexation with CB[6]. Localization of the positive charge is directly related to the length of the 1-alkyl chain on the imidazolium ring, which causes an induced local dipole subsequently allowing for an ion-dipole interaction with the carbonyl portal of CB[6].
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available